536 research outputs found

    Geotechnical Opportunities on a Fast-Track Bridge Project

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    The bridge for Nine Mile Road over Interstate 75 in Hazel Park, Michigan was destroyed by a tanker fire. The loss of the bridge was considered an emergency situation. Therefore, the bridge replacement was put on a fast-track schedule. Geotechnical engineering challenges included the design of shallow and deep foundations, design of light-weight backfill behind abutments, design of temporary earth retention systems to minimize traffic disruption during construction, and coordinating design changes during construction based on variable subsurface conditions. The design was based on the Bridge Design Specifications from the American Association of State Highway and Transportation Officials (AASHTO) Load and Resistance Factor Design (LRFD). Since the project involved replacement of a former bridge, the LRFD design could be compared with the previous foundations that were designed decades earlier. Thus, a summary was developed that identifies how the foundation types and sizes using LRFD methods changed, or remained unchanged, relative to the former bridge design using the Allowable Stress Design (ASD) method. The Michigan Department of Transportation (MDOT) elected to conduct the bridge replacement using the design-build approach. Total time to complete the design and construction of the new bridge: 65 calendar days

    Long-term results of corneal wedge resections for the correction of high astigmatism

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    Abstract We retrospectively evaluated 41 corneal wedge resections, performed for the correction of high astigmatism in 40 patients who were spectacle and contact lens intolerant. Keratometric astigmatism decreased from an average of 11.7 diopters (range 5 to 22.5 D) preoperatively to 3.5 diopters (range 0 to 10 D) postoperatively, representing a mean reduction of 8.2D (range 0 to 16.5), or 70%. The length of follow-up averaged 11 months. Twenty-five, 15 and 9 cases had a follow-up of at least 3, 5 and 10 years, respectively. In 16 cases the keratometry readings remained stable over the years. However, in 1 case of Fuchs' endothelial dystrophy (follow-up 13 years) and 5 cases of keratoconus (follow-up 3, 4, 12, 13 and 14 years) the astigmatism gradually increased during the various follow-up periods. In 3 other cases the astigmatism gradually decreased over the years. Corneal wedge resection is an effective technique for managing high corneal astigmatism. The results remain stable over the years except in some patients with keratoconus

    Terpene synthase genes originated from bacteria through horizontal gene transfer contribute to terpenoid diversity in fungi

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    Fungi are successful eukaryotes of wide distribution. They are known as rich producers of secondary metabolites, especially terpenoids, which are important for fungi-environment interactions. Horizontal gene transfer (HGT) is an important mechanism contributing to genetic innovation of fungi. However, it remains unclear whether HGT has played a role in creating the enormous chemical diversity of fungal terpenoids. Here we report that fungi have acquired terpene synthase genes (TPSs), which encode pivotal enzymes for terpenoid biosynthesis, from bacteria through HGT. Phylogenetic analysis placed the majority of fungal and bacterial TPS genes from diverse taxa into two clades, indicating ancient divergence. Nested in the bacterial TPS clade is a number of fungal TPS genes that are inferred as the outcome of HGT. These include a monophyletic clade of nine fungal TPS genes, designated as BTPSL for bacterial TPS-like genes, from eight species of related entomopathogenic fungi, including seven TPSs from six species in the genus Metarhizium. In vitro enzyme assays demonstrate that all seven BTPSL genes from the genus Metarhizium encode active enzymes with sesquiterpene synthase activities of two general product profiles. By analyzing the catalytic activity of two resurrected ancestral BTPSLs and one closely related bacterial TPS, the trajectory of functional evolution of BTPSLs after HGT from bacteria to fungi and functional divergence within Metarhizium could be traced. Using M. brunneum as a model species, both BTPSLs and typical fungal TPSs were demonstrated to be involved in the in vivo production of terpenoids, illustrating the general importance of HGT of TPS genes from bacteria as a mechanism contributing to terpenoid diversity in fungi

    Informed consent for suspension microlaryngoscopy:what should we tell the patient? A consensus statement of the European Laryngological Society

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    Introduction: Informed consent for any surgical intervention is necessary, as only well-informed patients can actively participate in the decision-making process about their care, and better understand the likely or potential outcomes of their treatment. No consensus exists on informed consent for suspension microlaryngoscopy (SML). Materials and methods: Informed consent procedures in nine countries on five continents were studied. Results: Several risks can be discerned: risks of SML as procedure, anesthesiologic risks of SML, specific risks of phonosurgery, risks of inadequate glottic exposure or unexpected findings, risks of not treating. SML has recognized potential complications, that can be divided in temporary (minor) complications, and lasting (major) complications. Conclusion: SML is a safe procedure with low morbidity, and virtually no mortality. Eleven recommendations are provided

    Higher risk of intracranial aneurysms and subarachnoid haemorrhage in siblings of families with intracranial aneurysms

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    Introduction: First-degree relatives of patients with familial aneurysmal subarachnoid hemorrhage have an increased risk of unruptured intracranial aneurysms and aneurysmal subarachnoid hemorrhage. We assessed whether the type of kinship of first-degree relatives of aneurysmal subarachnoid hemorrhage patients influences this risk. Patients and methods: We used all available data from the prospectively collected database of families consulting our outpatient clinic between 1994-2016. We constructed pedigrees for all families with ≥2 first-degree relatives with aneurysmal subarachnoid hemorrhage or unruptured intracranial aneurysms. The proband was defined as the first family member with aneurysmal subarachnoid hemorrhage who sought medical attention. We compared both the proportion of aneurysmal subarachnoid hemorrhage and unruptured intracranial aneurysms in proband's first-degree relatives by calculating relative risks (RR) with children as the reference. Results: We studied 154 families with 1,105 first-degree relatives of whom 146 had aneurysmalsubarachnoid hemorrhage. Unruptured intracranial aneurysms were identified in 63 (19%) of the 326 screened relatives. Siblings had a higher risk of aneurysmal subarachnoid hemorrhage (RR:1.62, 95% CI:1.12–2.38) and parents a lower risk (RR:0.44, 95% CI:0.24–0.81) than children. Siblings also had a higher risk of unruptured intracranial aneurysms (RR:2.28, 95% CI:1.23–4.07, age-adjusted RR:2.04, 95% CI:1.07–3.92) than children. Conclusion: Siblings of patients with aneurysmal subarachnoid hemorrhage have a significanthigher risk of both unruptured intracranial aneurysms and aneurysmal subarachnoid hemorrhage and parents have a lower risk of aneurysmal subarachnoid hemorrhage than children. Discussion: Type of kinship is a relevant factor to consider in risk prediction and screening advice in families with familial aneurysmal subarachnoid hemorrhage

    Spinal arteriovenous shunts presenting as intracranial subarachnoid haemorrhage

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    Item does not contain fulltextBACKGROUND: In approximately 5% of patients with intracranial subarachnoid haemorrhage (SAH), the cause is another than a ruptured aneurysm or perimesencephalic haemorrhage. One of these causes is a spinal arteriovenous shunt (SAVS). The aim of this study was to investigate the characteristics of patients with SAVS who present with intracranial SAH without symptoms and signs suggesting a spinal cause. METHODS: We systematically reviewed the literature and searched the SAH database of the University Medical Center Utrecht, The Netherlands, for patients with SAVS presenting with intracranial SAH and studied the characteristics of patients with SAVS whose clinical presentation mimicked intracranial SAH caused by rupture of a saccular aneurysm. RESULTS: Thirty-five patients were identified after a review of the literature. In our SAH database, comprising 2142 patients included in the period 1985-2004, we found one patient (0.05%, 95 % CI 0.006- 0.3%). SAH due to SAVS occurred at any age (4-72 years). The SAVS was located at the craniocervical junction in 14 patients, at the cervical level in 11, and at the thoracolumbar level in the remaining 11 patients. The majority of patients (n = 26, 72%) had no disabling deficits at discharge or follow-up. CONCLUSION: Rupture of a SAVS presenting as intracranial SAH is rare and can occur at any age. The SAVS can be located not only at the craniocervical junction or cervical level but also in the thoracolumbar region. Most patients with SAVS presenting as intracranial SAH have a good recovery
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